调控骨骼肌纤维类型转化的信号通路

Signaling Pathways in Skeletal Muscle Fiber-type Transition

骨骼肌由异质性的肌纤维组成,不同类型的肌纤维具有不同的形态、代谢、生理和生化特性.根据不同肌纤维中表达的特异肌球蛋白重链亚型可将成体哺乳动物骨骼肌纤维分为4类,即Ⅰ,Ⅱa,Ⅱx和Ⅱb型.骨骼肌保持高度可塑性,当机体受到某些生理或病理刺激时,骨骼肌为了适应需要,通过激活胞内相关信号通路改变肌纤维特异基因的表达从而诱发肌纤维类型的转化.本文综述了细胞内参与调控肌纤维类型转化的多条重要信号通路,如Ca2+信号通路,Ras/MAPK信号通路及多种转录调节因子,辅激活因子和抑制子等,为改善肉类品质,提高运动训练效果及治疗肌肉相关疾病奠定了理论基础.

Skeletal muscle is comprised of heterogeneous muscle fibers that differ in their size, metabolic, biophysical and biochemical characteristics. The objective approach to muscle fiber typing based on the specific myosin heavy chain isoform expression, mature skeletal myofibers are classified into type I , I[ a, ]1 x and lIb fibers. Under several physiological and pathological circumstances, skeletal muscle could transduce this stimuli into molecular signals that alter fiber-type gene expression. Here we review several possible signaling pathways that may contribute to the fiber-type transition, such as various components of calcium-dependent signaling pathways and multiple transcription factors, coactivators and corepressors. Understanding the mechanisms involved in modulating skeletal muscle phenotypes can potentiate the development of meat quality, exercise training and new therapeutic measures to ameliorate muscular diseases.